It is better to use “State Button” rather than “Push Button” in app designer in your use case. When the Push Button is clicked once, the button appears to press and release. When the State Button is clicked, the button remains in the pressed or released state until it is clicked again. Use the “value” variable in the ButtonValueChanged callback of the State Button to run or stop your motor. Look at the following callback code of State Button which might help you.
function ButtonValueChanged(app, event)
value = app.Button.Value;
if value==1
% command to run motor
else
% command to stop motor
end
end